盛方正, 王文成, 陈亚子. 电流互感器二次侧并联接入变压器差动保护装置的问题研究[J]. 现代电力, 2011, 28(4): 35-39.
引用本文: 盛方正, 王文成, 陈亚子. 电流互感器二次侧并联接入变压器差动保护装置的问题研究[J]. 现代电力, 2011, 28(4): 35-39.
SHENG Fangzheng, WANG Wencheng, CHEN Yazi. Research on Parallel Access of Transformer Differential ProtectionDevice at the Secondary Side of CT[J]. Modern Electric Power, 2011, 28(4): 35-39.
Citation: SHENG Fangzheng, WANG Wencheng, CHEN Yazi. Research on Parallel Access of Transformer Differential ProtectionDevice at the Secondary Side of CT[J]. Modern Electric Power, 2011, 28(4): 35-39.

电流互感器二次侧并联接入变压器差动保护装置的问题研究

Research on Parallel Access of Transformer Differential ProtectionDevice at the Secondary Side of CT

  • 摘要: 差动保护作为主保护, 必须保证能够准确快速地切除故障并防止误动。以内桥接线变压器为研究对象, 分析了在差动保护电流互感器二次侧并联接入保护装置的情况下, 当保护区内、区外发生故障时差动保护的动作情况, 分析发现当保护区外故障以及近侧变压器空载合闸后, 由于制动电流很小, 电流互感器严重饱和, 因而产生很大的不平衡电流可能导致比率制动的差动保护误动。仿真结果表明在近侧变压器空载合闸时, 带负荷变压器的电流波形严重恶化, 差动电流突然增加并且二次谐波含量过低从而使得差动保护误动。最后提出了相应防范对策。

     

    Abstract: Differential protection is the primary protection, and it should remove the fault accurately and rapidly without malfunction. In this paper, as to the transformers in the way of internal bridge connection, the action of differential protection in fault protection region is analyzed when protection devices are parallel accessed into the secondary side of differential CT, which will detect fault outside of protection region and malfunction of differential protection with ratio braking caused by large unbalance current because of small braking current and serious saturation of CT after no-load closing of transformer at near side. It can be found from the simulation that the current waveform of transformer with load deteriorates rapidly when transformer at near side closes with no load, which will make differential current increase suddenly and the content of second harmonics is too low, therefore cause the maloperation of differential protection. In the end, the corresponding measures are proposed.

     

/

返回文章
返回